fixed uninitialized constant buffer memory

src/renderer_mtl.mm

@@ -3953,7 +3953,6 @@ namespace bgfx { namespace mtl
 					const RenderCompute& compute = renderItem.compute;
 
 					bool programChanged = false;
-					bool constantsChanged = compute.m_uniformBegin < compute.m_uniformEnd;
 					rendererUpdateUniforms(this, _render->m_uniformBuffer[compute.m_uniformIdx], compute.m_uniformBegin, compute.m_uniformEnd);
 
 					if (key.m_program.idx != currentProgram.idx)
@@ -3969,8 +3968,7 @@ namespace bgfx { namespace mtl
 						}
 
 						m_computeCommandEncoder.setComputePipelineState(currentPso->m_cps);
-						programChanged =
-							constantsChanged = true;
+						programChanged = true;
 					}
 
 					if (isValid(currentProgram)
@@ -3984,13 +3982,10 @@ namespace bgfx { namespace mtl
 							m_computeCommandEncoder.setBuffer(m_uniformBuffer, m_uniformBufferVertexOffset, 0);
 						}
 
-						if (constantsChanged)
+						UniformBuffer* vcb = currentPso->m_vshConstantBuffer;
+						if (NULL != vcb)
 						{
-							UniformBuffer* vcb = currentPso->m_vshConstantBuffer;
-							if (NULL != vcb)
-							{
-								commit(*vcb);
-							}
+							commit(*vcb);
 						}
 
 						viewState.setPredefined<4>(this, view, *currentPso, _render, compute);
@@ -4233,7 +4228,6 @@ namespace bgfx { namespace mtl
 				}
 
 				bool programChanged = false;
-				bool constantsChanged = draw.m_uniformBegin < draw.m_uniformEnd;
 				rendererUpdateUniforms(this, _render->m_uniformBuffer[draw.m_uniformIdx], draw.m_uniformBegin, draw.m_uniformEnd);
 
 				bool vertexStreamChanged = hasVertexStreamChanged(currentState, draw);
@@ -4333,8 +4327,7 @@ namespace bgfx { namespace mtl
 						rce.setVertexBuffer(inst.m_ptr, draw.m_instanceDataOffset, numStreams+1);
 					}
 
-					programChanged =
-						constantsChanged = true;
+					programChanged = true;
 				}
 
 				if (isValid(currentProgram) )
@@ -4355,19 +4348,16 @@ namespace bgfx { namespace mtl
 						rce.setFragmentBuffer(m_uniformBuffer, m_uniformBufferFragmentOffset, 0);
 					}
 
-					if (constantsChanged)
+					UniformBuffer* vcb = currentPso->m_vshConstantBuffer;
+					if (NULL != vcb)
 					{
-						UniformBuffer* vcb = currentPso->m_vshConstantBuffer;
-						if (NULL != vcb)
-						{
-							commit(*vcb);
-						}
-
-						UniformBuffer* fcb = currentPso->m_fshConstantBuffer;
-						if (NULL != fcb)
-						{
-							commit(*fcb);
-						}
+						commit(*vcb);
+					}
+					
+					UniformBuffer* fcb = currentPso->m_fshConstantBuffer;
+					if (NULL != fcb)
+					{
+						commit(*fcb);
 					}
 
 					viewState.setPredefined<4>(this, view, *currentPso, _render, draw);